In the sport of archery the bow string is drawn to tension the bow, and in its elementary manner the bow string is grasped by the ends of the fingers during drawing. As release of the bow string by the fingers may produce string deviation during release, and also imposes high stress upon the fingers, string and arrow release devices are commonly used to aid in the drawing of the string and releasing the string and arrow to alleviate the problems attendant with finger operation.
A wide variety of bow string release devices are known, and typical examples are shown in U.S. Pat. No. 1,542,159; 3,948,243; 4,036,204; 4,282,851; 4,407,260 and 4,881,516. The bow string and arrow release devices shown in the aforementioned patents include pivoted retainers for the string or arrow, toggle and clamp actuators, triggers, cams, and a variety of mechanical motions to achieve the desired result. However, bow string releases presently available do not achieve the ease and smoothness of action and lack of deviation during release to achieve utmost accuracy, and it is a purpose of the invention to overcome these deficiencies of prior art devices and provide a bow string release of superior accuracy.
It is an object of the invention to provide a bow string release utilizing pivoted string retainers and pivoted retainer operators wherein the bow string is released by a squeezing or pinching action of the fingers minimizing deviation of the release during triggering.
A further object of the invention is to provide a bow string release of concise configuration, easy to handle, and wherein superior accuracy is achieved during release by the application of uniform opposing forces to the release during triggering.
An additional important object of the invention is to provide a bow string release employing pivoted string retainers, pivoted retainer operators, and a toggle mechanism between the retainers and operators employing a three point pivot axis system wherein a near on-center relationship between the pivot axes is achieved during string retention maximizing the force produced to maintain the retainers in a string retaining condition, yet also minimizing the force required to trigger the release.
A further object of the invention is to provide a bow string release using pivoted string retainers wherein safety means are associated with the retainers preventing pivoting thereof to a string releasing position during the bow string draw.
A further object of the invention is to provide a bow string release used in conjunction with a wrist strap wherein the release body is pivotally mounted to the wrist strap and a swivel connection utilizes a built-in adjustment which is easily operable without tools for regulating the position of the release relative to the strap.
Another object of the invention is to provide a bow string release using a wrist strap in combination with rigid adjustable arms whereby the pivoting of the arms permits the wrist strap size to be adjusted once for a particular archer and the hand may be inserted through the wrist strap without further strap adjustment.
The bow string release consists of an elongated body which may be easily held within the archer's string drawing hand and the body is connected to a wrist strap by a swivel connection wherein the primary drawing forces transferred to the body are through the wrist strap minimizing the grasping force required on the body.
The body, basically, consists of upper and lower plates having a pair of string retainers pivotally mounted thereon each including a configured jaw portion defining a recess in which the bow string may be located during drawing. A pair of retainer operators in the form of levers are mounted upon the body between the plates and include handle portions laterally extending from opposite sides of the body wherein the operators may be simultaneously actuated by a pinching or squeezing action applied to the handle portions. The operators include lever portions connected to a toggle linkage located between the retainer operators and the retainers.
The toggle linkage includes three parallel pivots which are substantially aligned in the same plane during the closing of the retainers during the string drawing operation. The substantially on-center relationship of the center toggle pivot with respect to the end pivots permits high forces to be imposed upon the retainers by the bow string endeavoring to open the retainers without such opening occurring, and pivoting of the retainer operators displaces the center toggle pivot so as to permit the retainers to readily pivot to a string releasing position in a smooth non-deviating manner. The retainer operators may be pre-adjusted so that only a slight pivoting of the operators will permit the toggle linkage to release providing a "hair" trigger and optimum accuracy.
A safety device in the form of a spring biased finger operated button and stop is mounted upon the body selectively positionable adjacent the toggle linkage center pivot and the safety device prevents pivoting of the toggle linkage to a string releasing position, which significantly contributes to the safe operation of the release during string drawing.
As the position of the release body to the wrist strap is important from the standpoint of comfort and ease of operation a universal swivelable interconnection is interposed between the wrist strap and the release body utilizing an axially adjustable screw. The axial position of the screw is readily adjusted through a built-in hexagonal wrench system which is operable only when tension forces on the release body and wrist strap are relieved.
Optimum accuracy is considered to be achieved when the retainer operator handle portions are pinched or squeezed by the application of opposed forces to the handle portions by the fingers. However, some archers prefer a bow release to have a trigger wherein release can be achieved by pulling the trigger toward the archer. The release of the invention includes such a trigger selectively positionable between operative and inoperative positions on one of the retainer operators, and a spring biased detent maintains the trigger in the desired position.